Make sure getVisitorProfilePopup isn't used in the dashboard UI tests.
Refs #4041, refactored jqplot datatable visualizations (mainly the evolution graph),

Notes:
  - Fix bugs in DataTable class where getRowFromLabel would fail if summary row label is returned.
  - Fix regression caused by datatable visualization refactor (add_total_row property was effectively ignored).
  - Added x_axis_step_size property to jqplot graph.
Refs #4041, small tweak to last commit.